Georgetown Uranium Project
Callabonna Uranium’s Queensland projects are centred on the highly prospective Georgetown Inlier of northern Queensland. The Georgetown region contains numerous well known high grade uranium deposits including the Maureen uranium deposit, the Ben Lomond deposit and the Trident and Lineament groups of deposits (all owned by Mega Uranium).
The Maureen Deposit is located 2-5kms north of Callabonna’s Huonfels project and in July 2008 Mega announced a NI43-101 compliant resource for the Maureen deposit totalling some 6.33Mlbs U3O8. Mega’s website also quotes potential high grade resources at their nearby Trident Project (including Four Geo, Two Geo and Quartz Blow Deposits) and the Lineament Fault Zone. Deposits within these two projects have a significant historical resource attributed to them at an average grade of 0.1% U3O8 . Mega's Trident project is situated immediately south of Callabonna Uranium’s "Neptune" Project on the same major structural zone that extends through the Neptune Project lease area. Uranium mineralisation within the Georgetown Region is thought to be volcanogenic in nature and similar to the Streltsovskoye District of western Russia where total resources of over 700Mlbs U3O8 have been defined.
Callabonna is using recent insights into these massive volcanogenic uranium districts and applying them to the Georgetown District to explore for “blind” uranium deposits at depth within the volcanic calderas or depressions.
Exploration Model – Volcanogenic Uranium Deposits
The Streltsovskoye District of western Russia contains 18 defined uranium deposits hosted within the 20km wide Tulukuyevsk Caldera. Combined the deposits are thought to represent the largest volcanogenic uranium resource in the world at 727 Mlb U3O8 with ores grading at more than 0.2% (Nash, 2010). Within the Tulukuyevsk Caldera, uranium mineralisation is controlled by structural features and occurs as stratiform mineralisation in sediments or fracture controlled mineralisation in volcanics and/or granites. Importantly, most of the Streltsovskoye deposits have no distinct surficial radiometric anomalies.
The Georgetown geological province hosts a number of Carboniferous aged caldera complexes that have a spatial association with most/all of the uranium occurrences within the region. The vast majority of historic uranium exploration within the Georgetown province has focused upon prominent surface radiometric anomalies identified with airborne or ground geophysical surveys and generally associated with caldera margins or regional structures. Callabonna believes there is enormous unrealised prospectivity for ‘Streltsovskoye’ style volcanogenic mineralisation within the interior of the Georgetown calderas and that previously discovered deposits may represent only minor occurrences (“smoke”) within a very large uranium camp. Only a small number of shallowly drilled exploration holes have been completed within the calderas and most of these have been for epithermal gold mineralisation rather than uranium. Airborne magnetic data and mapping will be used for delineation of deep penetrating geological structures and MMI (Mobile Metal Ion) soil geochemistry focussed on known geochemical associations will be used to highlight prospective structural zones for drill testing.
Table 1 Volcanogenic deposit size and grade - Australia and Russia
(Dahlkamp, 2009) (Mega Uranium Ltd, 2010)
| Region | Deposit | Contained U3O8 | Grade | Co-/by-product |
|---|---|---|---|---|
| Georgetown (Aus) | Maureen | 6.48 Mlb (2,940 t) | 0.123% | Mo + F |
| Two Gee, Four Geo, Qtz Blow | 6.4 Mlb (2,903 t) | 0.1% | Mo | |
| Townsville (Aus) | Ben Lomond | 14.97 Mlb (6,792 t) | 0.228% | Mo |
| Streltsovskoye (Rus) | Streltsovskoye | 184.53 Mlb (83,700 t) | 0.19% | Mo |
| Antel | 103.84 Mlb (47,100 t) | 0.30% | Mo + F | |
| Argunskoye | 77.82 Mlb (35,300 t) | 0.17% | Mo | |
| Oktyabrskoye | 59.74 Mlb (27,100 t) | 0.25% | Mo | |
| Tulukuyevskoye | 96.12 Mlb (43,600 t) | 0.24% | Mo |
Figure A: Map of Streltsovsk District with surface projections of uranium deposits in the Tulukuyevsk Caldera. Note association of mineralisation with major structures and that stratiform and fracture style minerlisation are often adjacent to each other.
Works Cited
Dahlkamp Franz J. Uranium Deposits of the World - Asia [Journal]. - Hamburg : Sprnger, 2009.
Mega Uranium Ltd Georgetown Projects [Online] // Mega Uranium Company Site. - Mega Uranium Ltd, 2010. - 28 September 2010. - http://www.megauranium.com/main/index.php?georgetown.
Nash J. Thomas Volcanogenic uranium deposits—Geology, geochemical processes, and criteria for resource assessment: [Journal]. - [s.l.] : U.S. Geological Survey, 2010. - Vols. Open File Report 2010-1001. - p. 99.
